1. Field of the Invention
The present invention relates to a semiconductor device, and specifically, relates to a semiconductor device with reduced insertion loss.
2. Description of the Related Art
In mobile communication devices such as cellular phones microwaves in the GHz range are often used and switching devices to switch high frequency signals in circuits to switch antennas, transmitting/receiving, or the like are used in many cases (for example, Japanese Patent Application Publication No. 9-181642). In the switching device, a field-effect transistor (hereinafter, referred to as an FET) using gallium arsenide (GaAs) is used in many cases because the device deals with microwaves. Accordingly, a monolithic microwave integrated circuit (MMIC) in which the above switch circuit is integrated has been developed.
For example, the MMIC is a compound semiconductor circuit device called a single pole double throw (SPDT), in which a plurality of stages of FETs are connected in series to achieve high power. Relevant technologies are described in, for example, Japanese Patent Application Publication No. 2004-254086.